Programmable circuit for drift compensation

Abstract

Systems and methods relating to programmable circuits are described. Several embodiments relate to systems and methods for controlling the long-term stability and accuracy of circuits that produce waveforms varying in frequency and amplitude. Such embodiments may include a circuit comprising a common vacuum environment that houses a pair of heater-thermocouples. The circuit may compare signals outputted by each heater-thermocouple and then may produce a resultant value based on the comparison. The resultant value may be used by the circuit to control the long-term stability and accuracy of the circuit. Such control of the long-term stability and accuracy of the circuit may include drift compensation associated with certain components of the circuit.

What is claimed is: 
     
       1. A compensation system, comprising:
 a structure defining a common vacuum environment; and 
 a compensation arrangement disposed within the common vacuum environment, the arrangement including:
 a first input that delivers first signal to a first heater wherein the first heater is thermally connected to a first thermocouple; 
 a second input that delivers a second signal to a second heater, wherein the second heater is thermally connected to a second thermocouple; 
 a first output that outputs a third signal received from the first thermocouple; and 
 a second output that outputs a fourth signal received from the second thermocouple. 
 
 
     
     
       2. The system of  claim 1 , further comprising:
 a first component that compares the third signal with the fourth signal and produces a fifth signal based on the comparison between the third signal and the fourth signal; and 
 a second component that operates upon the fifth signal to compensate for drift associated with a third component. 
 
     
     
       3. The system of  claim 2 , wherein the second component is a signal source. 
     
     
       4. The system of  claim 2 , wherein the third component is disposed within the common vacuum environment. 
     
     
       5. The system of  claim 2 , wherein the third component is a circuit connection that generates thermal EMF errors. 
     
     
       6. The system of  claim 2 , wherein the third component is a non-ideal amplifier. 
     
     
       7. The system of  claim 2 , wherein the third component is a heater-thermocouple. 
     
     
       8. The system of  claim 2 , wherein the first component is an error amplifier comprising a first error amplifier input, a second error amplifier input and an error amplifier output, wherein the first error amplifier input is operable to receive the third signal, wherein the second error amplifier input is operable to receive the fourth signal, and wherein the error amplifier output is operable to output the fifth signal. 
     
     
       9. A system including circuitry, comprising:
 a signal source that produces a source signal; 
 a comparator having a first input, a second input and an output, wherein the first input receives a first signal, wherein the second input receives a second signal, and wherein the output produces an output signal based on a comparison between the first signal and the second signal; and 
 a measurement device that measures the output signal produced by the comparator to achieve a measurement value, wherein the signal source adjusts the output signal of the comparator in response to the measurement value. 
 
     
     
       10. The system of  claim 9 , wherein the first signal is derived from the signal source, and wherein the second signal is derived from the signal source. 
     
     
       11. The system of  claim 9 , wherein the first signal is derived from the signal source, and wherein the second signal is derived from the output of the comparator. 
     
     
       12. The system of  claim 9 , wherein the adjustment of the output signal compensates for drift of a system component. 
     
     
       13. The system of  claim 9 , wherein the comparator comprises a common vacuum environment including a first thermocouple and a second thermocouple. 
     
     
       14. The system of  claim 12 , wherein the system component is a common vacuum environment including a first thermocouple and a second thermocouple. 
     
     
       15. The system of  claim 12 , wherein the system component is a circuit connection that generates thermal EMF errors. 
     
     
       16. The system of  claim 12 , wherein the system component is a non-ideal amplifier. 
     
     
       17. The system of  claim 12 , wherein the system component is a heater-thermocouple.